L-DEPRENYL-D2 C-11 is a selective irreversible inhibitor of monoamine oxidase B (Mao-B) which labels functionally active enzyme. It is used as a positron emission tomography radioligand for measurement of the Mao-B activity in vivo brain.

Tyroserleutide (YSL) is a tripeptide treatment being developed by Shenzhen Kangzhe Pharmaceutical Co Ltd, a subsidary of China Medical System Holdings (CMS), for the treatment of liver cancer. It is initially separated and purified from the hydrolyzates of pig’s spleen, but now can be obtained by chemical synthesis, its chemical name is L-tyrosine-L-serine-L-leucine. Tyroserleutide is an active, low-molecular-weight polypeptide, comprised of three amino acids, that has shown antitumor effects on human hepatocarcinoma BEL-7402 in vitro and in vivo. Tyroserleutide has various advantages over the other bioactive peptides such as its low molecular weight, simple construction, nonimmunogenicity, specificity, few side effects, and ease of synthesis. Tyroserleutide is in Phase-III clinical trials for the treatment of liver cancer.

METHYLENETETRAHYDROFOLIC ACID, L-(+), an endogenous biomodulator that was developed under the brand name modufolin or arfolitixorin by the Isofol Medical. Arfolitixorin is developed to increase the efficacy of standard of care chemotherapy for advanced colorectal cancer. This drug is currently being studied in a global phase 3 clinical trial. Besides, the drug successfully completed phase II as rescue therapy for osteosarcoma. 21 May 2019 Isofol Medical has received clinical patent protection for the arfolitixorinin USA. It relates to a method of increasing blood concentration of deoxyuridine, a blood biomarker for inhibition of tumor growth in human cancer treatment.

Clevudine F18 is a radioconjugate comprised of the synthetic pyrimidine analog clevudine (1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)thymine, d-FMAU) labeled with the radioisotope fluorine F18. Upon administration, fluorine F18 clevudine is distributed and taken up by cells based on the rate of the cell’s DNA synthesis. The amount is then measured using positron emission tomography (PET). The compound is investigated as an imaging agent in prostate, breast cancers, and other malignant neoplasms.

Ore Pharmaceuticals developed ORE1001 previously known as MLN-4760 as an orally administered, small molecule compound, for the treatment of inflammatory bowel diseases. ORE1001 is a specific angiotensin-converting enzyme 2 inhibitor. It was shown that ORE1001 markedly decreased tissue myeloperoxidase activity, a well-known marker of inflammation. As a result, ORE1001 was studied as a treatment of gastrointestinal inflammatory conditions. ORE1001 was involved in phase I clinical trial to investigate its safety and activity in subjects with ulcerative colitis. In addition, the drug was studied for NSAID-induced ulcer and obesity. However, all these studies were discontinued.

Belnacasan (VX-765), and its active metabolite VRT- 043198, is a novel and irreversible IL-converting enzyme/ caspase-1 inhibitor. VRT-043198 exhibits 100- to 10,000-fold selectivity against other caspase-3, -6 and -9. It exhibited potent inhibition against ICE/caspase-1 and caspase-4 with Ki of 0.8 nM and less than 0.6 nM, respectively. And VRT-043198 also inhibits IL-1β release from both PBMCs and whole blood with IC50 of 0.67 uM and 1.9 uM, respectively. Belnacasan inhibits the release of IL-1, IL-18 and IL-33. Belnacasan has shown to inhibit acute partial seizures in preclinical models and has shown activity in preclinical models of chronic partial epilepsy that do not respond to currently available compounds for epilepsy. In addition, it seems to reduce disease severity and the expression of inflammatory mediators in models of rheumatoid arthritis and skin inflammation. Belnacasan had been in phase II clinical trials by Vertex for the treatment of epilepsy. However, this study has been terminated later.

MIP-1095 I-123 is under investigation in clinical trial phase II to evaluate the safety and efficacy in combination with enzalutamide in patients with prostate-specific membrane antigen (PSMA)-avid metastatic castration-resistant prostate cancer who have progressed on abiraterone. It is known that MIP-1095 potently inhibited the glutamate carboxypeptidase activity of PSMA and when radiolabeled with 123I exhibited high affinity for prostate-specific membrane antigen (PSMA) on human prostate cancer LNCaP cells.

Foxy-5, a wingless-type mammary tumor virus integration site 5A (WNT5A)-mimicking peptide, was studied for the treatment of cancer. Foxy-5 is participating in phase II clinical trial as neo-adjuvant therapy for the treatment of patients with wnt-5a low colon cancer. Besides, Foxy-5 was used in phase I clinical trial, for the treatment of prostate cancer patients with tumors exhibiting absent or low WNT5A expression.

Oleandrin is a toxic cardiac glycoside found in oleander (Nerium oleander L.). Along with neandrin it is primarily responsible for the toxicity of the sap of oleander. Oleandrin has been used for many years in China and Russia for its properties as a cardiac glycoside, for both suicidal and therapeutic purposes as in treatment of cardiac insufficiency. Because of its properties as a cardiac glycoside, oleandrin interferes in some essential processes within the cell, the most important of these being the inhibition of the Na-K ATPase. This protein enables the cell to exchange the cations Na+ and K+ between the intercellular and extracellular spaces by which, for instance, electronic signaling is made possible in nerve cells. Oleandrin binds to specific amino acids in the protein, causing it to lose its function. After depolarization of the cell in which Na+ flows into the cell, the Na+ cannot be transported back into the extracellular membrane, causing the sodium gradient to disappear. This gradient is the driving force for other transport proteins, such as the sodium-calcium exchanger, which plays an important role in cardiomyocytes. To make muscle contraction possible, a calcium influx from the extracellular fluid into the cell is crucial. After the muscle contraction, the calcium is normally pumped out of the cell and exchanged for sodium. When the sodium gradient is depleted, calcium cannot be pumped back and, as a consequence, accumulates in the cardiomyocyte. As a result of the high calcium concentration, actin and myosin filaments will bind stronger, unable to relax properly to make a new contraction possible. This may result in cardiac arrhythmias, in the worst case decreasing cardiac output and causing a shortage in oxygen supply in vital tissues. Apart from being a potent toxic compound, it may also be used in therapeutic ways. Both oleandrin and oleandrigenin, as well as their relatives, may be able to inhibit proliferation of tumor cells and stimulate their apoptosis as a result of the high concentration of intracellular calcium. In addition, it inhibits excretion of fibroblast growth factor 2 through membrane interaction and through inhibition of the Na,K-ATPase pump. However, there are no results from clinical testing on humans that support any use as a cancer treatment. Oleandrin has been reported to be lethal, but exact dosages are not fully documented. The fatal blood concentration of oleandrin has been estimated for humans to be approximately 20 ng/ml in decreased blood by extrapolation of intoxication symptoms. Symptoms present in poisoned animals include bloody diarrhea and colic, the latter especially in horses. Because the leaf itself is quite bitter, only starving animals will be likely to eat the plant. The lethal dosage for animals is estimated to be about 0.5 mg/kg.